Canada Jet Charters' standard operating procedures (SOPs) call for the before-landing checklist to be completed prior to the aircraft passing the FAF on a non-precision approach. This was not done despite the landing gear warning horn sounding four times before the FAF, and a further three times between the FAF and touchdown. Each time the horn sounded, it was silenced by the crew. At two miles from the runway, on final approach, when the captain remarked that he could not see the PAPI, the captain became occupied with getting the PAPI turned on. As a result, the intensity of the runway lights was increased, requiring a further call from the captain. These distractions, and the numerous radio transmissions to the aircraft regarding the Sandspit weather, likely resulted in the crew forgetting that the gear had not been extended and the before-landing checklist not completed.Analysis Canada Jet Charters' standard operating procedures (SOPs) call for the before-landing checklist to be completed prior to the aircraft passing the FAF on a non-precision approach. This was not done despite the landing gear warning horn sounding four times before the FAF, and a further three times between the FAF and touchdown. Each time the horn sounded, it was silenced by the crew. At two miles from the runway, on final approach, when the captain remarked that he could not see the PAPI, the captain became occupied with getting the PAPI turned on. As a result, the intensity of the runway lights was increased, requiring a further call from the captain. These distractions, and the numerous radio transmissions to the aircraft regarding the Sandspit weather, likely resulted in the crew forgetting that the gear had not been extended and the before-landing checklist not completed. The crew did not complete the before-landing checks, ignored aural warnings, and did not lower the landing gear, which resulted in a gear-up landing.Findings as to Causes and Contributing Factors The crew did not complete the before-landing checks, ignored aural warnings, and did not lower the landing gear, which resulted in a gear-up landing. The aircraft was not equipped with a GPWS, which could have prevented this accident. The before-landing checklist in use did not reflect the AFM requirement that the speed brakes should be retracted prior to 50feet.Findings as to Risk The aircraft was not equipped with a GPWS, which could have prevented this accident. The before-landing checklist in use did not reflect the AFM requirement that the speed brakes should be retracted prior to 50feet. On 10January2003, the TSB issued an Aviation Safety Information Letter to Transport Canada, with a copy to the B. C. Ambulance Service, regarding the design of the Cessna Citation550 landing gear warning system. The letter also showed that a GPWS would provide defences against the risk of landing with the landing gear retracted. As a result of the letter, the B. C. Ambulance Service decided to require the fitting of a GPWS system to all fixed wing aircraft operated on their behalf by contracted carriers. On 14 February 2003, Transport Canada responded, describing a proposed amendment to the Canadian Aviation Regulations regarding implementation of ClassA and ClassB Terrain Avoidance Warning Systems (TAWS). The response letter indicated that if the amendments were promulgated, and depending on class, installation and operator, TAWS might provide defences against landing with gear retracted. These proposed amendments have subsequently been accepted in principle. If the proposals become regulations, they will require aircraft such as the Cessna Citation550 to be equipped with TAWS. A C550 operating under CAR704 would require, as a minimum, a ClassB TAWS if configured with six to nine passenger seats. A ClassA TAWS with a display would be required for an aircraft configured with 10or more passenger seats. There would be no requirement for an aircraft configured like the occurrence aircraft to be equipped with TAWS. This report concludes the TSB's investigation into this occurrence. Consequently, the Board authorized the release of this report on 03July2003. 1. All times are Pacific standard time (Coordinated Universal Time minus eight hours) unless otherwise noted.Safety Action On 10January2003, the TSB issued an Aviation Safety Information Letter to Transport Canada, with a copy to the B. C. Ambulance Service, regarding the design of the Cessna Citation550 landing gear warning system. The letter also showed that a GPWS would provide defences against the risk of landing with the landing gear retracted. As a result of the letter, the B. C. Ambulance Service decided to require the fitting of a GPWS system to all fixed wing aircraft operated on their behalf by contracted carriers. On 14 February 2003, Transport Canada responded, describing a proposed amendment to the Canadian Aviation Regulations regarding implementation of ClassA and ClassB Terrain Avoidance Warning Systems (TAWS). The response letter indicated that if the amendments were promulgated, and depending on class, installation and operator, TAWS might provide defences against landing with gear retracted. These proposed amendments have subsequently been accepted in principle. If the proposals become regulations, they will require aircraft such as the Cessna Citation550 to be equipped with TAWS. A C550 operating under CAR704 would require, as a minimum, a ClassB TAWS if configured with six to nine passenger seats. A ClassA TAWS with a display would be required for an aircraft configured with 10or more passenger seats. There would be no requirement for an aircraft configured like the occurrence aircraft to be equipped with TAWS. This report concludes the TSB's investigation into this occurrence. Consequently, the Board authorized the release of this report on 03July2003. 1. All times are Pacific standard time (Coordinated Universal Time minus eight hours) unless otherwise noted.